Problem: If $x \triangleright y = x-4y$ and $x \triangleleft y = 4x-3$, find $(4 \triangleleft 4) \triangleright -3$.
Explanation: First, find $4 \triangleleft 4$ $ 4 \triangleleft 4 = (4)(4)-3$ $ \hphantom{4 \triangleleft 4} = 13$ Now, find $13 \triangleright -3$ $ 13 \triangleright -3 = 13-(4)(-3)$ $ \hphantom{13 \triangleright -3} = 25$.